package demo.genericity;

import org.w3c.dom.Node;

import java.util.LinkedList;

/**
 * 内部链式存储
 *
 * @author sun.ye
 * @since 2020-07-05 17:08
 */
public class LinkedStack<T> {
    private static class Node<U> {
        U item;
        Node<U> next;
        Node(){
            item = null;
            next = null;
        }

        public Node(U item, Node<U> next) {
            this.item = item;
            this.next = next;
        }

        boolean end() {
            return item == null && next == null;
        }
    }

    private Node<T> top = new Node<>();

    public void push(T item){
        top = new Node<>(item,top);
    }

    public T pop(){
        T result = top.item;
        if (!top.end()) {
            top = top.next;
        }
        return result;
    }

    public static void main(String[] args) {
        LinkedStack<String> linkedStack = new LinkedStack<>();
        for (String s : "Phasers on stun !".split(" ") ) {
            linkedStack.push(s);
        }
        String s;
        while ((s = linkedStack.pop()) != null){
            System.out.println(s);
        }
    }
}